Felt the desire to share with the board, how comically inadequate is the forced air ductwork in my house, in winter heating mode. Currently with a cold (for S.Texas) night, am seeing 7 degrees difference between temperature at the thermostat, and temperature in the master bedroom and bath(!). Thankfully it is the master bath which is the warmer location.
At present I think the system airflow is reasonably close to optimum in cooling mode, but the heat loss per room is very different in winter. My room by room Manual J calc shows the heating load is distributed differently than cooling load. Therefore there is no one solution for airflow in both modes, just a compromise. I do believe what I am seeing also tells me actual heating loads are kinda different from the Manual J model.
Overall there is enough heating capacity with two-stage Trane gas furnaces, it just has trouble getting distributed to the right rooms. I don't have much hope that this can be completely fixed without having special ducts for heating vs. cooling, or thermostats in the problem areas controlling some kind of local heating. I may be a nut but not nutty enough to do a Rube Goldberg thing here. If anyone here has suggestions then I am eager to hear them and try to implement them, but the way our S.Texas winters go the winter will be gone before too many things can be tried. I am trying little things like running the (VS) air handler continuously for parts of the day.
Way back in 2003 I had noticed one bedroom being a few degrees colder, that got me started on this whole odyssey of trying to learn what a consumer might need to know about HVAC. Tried to employ some professionals in this case, with little results. Cannot blame them for lack of expertise in winter problems, not in a cooling dominated climate like S.Texas. Too much of a niche problem for them.
As long as the whole system works in the long summer, I can grin and bear its shortcomings our rather short winter.
Best wishes all -- Pstu
[Edited by pstu on 12-02-2006 at 10:15 PM]